For the supplementation of the fire resistance tests of popular trees in Japan, reported by the writer on this journal in Vol. 33, p. 367_??_372, 1951, I made the following tests about deciduous trees and bamboos, covering 30 species, in September 1955.
Heating source was a horizontal cylindrical electric furnace maintained at constant temperature 500°C. Fresh leaves were carried in the heart of the furnace, hanging from hooks on a rail. Find the further descriptions on the equipment, processes and operations in the paper aforesaid.
Results obtained are shown in Table 2. Regarding the marks of the combustion types, see the paper above-mentioned.
Generally speaking, leaves take time for the blazing up as 7.5_??_19 seconds among deciduous broad-leaves, 10-28 sec. among evergreen broad-leaves, 22_??_40 sec. among conifers.
Deciduous broad-leaves seem far less fire-resistive than evergreens and are especially poor in the defoliation for the fire-preventive plantings.
Yet I have found some fire-resistive plants among them, such as Hydrangea macrophylla and Deutzia crenata in their foliate state. Species on the antipole are bamboos and next come Zelkowa serrata, Aphananthe aspera, Robinia pseudo-Acacia etc.